Vehicle with elastomeric bearing suspension system and elastomeric bearing therefor

ABSTRACT

A vehicle suspension system for large vehicles includes at least one elastomeric bearing. The bearing includes at least one substantially cylindrical elastomeric portion, at least one substantially frustospherical elastomeric portion, and at least one non-extensible shim disposed between and bonded to the substantially cylindrical elastomeric portion and the substantially frustospherical elastomeric portion.

CROSS REFERENCE

This Application claims priority to U.S. Provisional Patent Application60/828,473 filed on Oct. 6, 2006 which is hereby incorporated byreference.

FIELD OF THE INVENTION

The invention is directed to suspension systems for large vehicles suchas tracked earth-moving vehicles. More particularly, the invention isdirected to a vehicle suspension system having at least one elastomericbearing.

BACKGROUND INFORMATION

Tractors and other large earth-moving vehicles (referred to herein as“dozers” or “tracked vehicles”) often include an equalizer link thatconnects the dozer's cab structure to its moving tracks or wheels. Theequalizer link acts to substantially equally laterally distribute adozer's weight between the dozer's tracks or wheels. The equalizer linktypically includes a beam constructed of hot-rolled or forged steel.Bearings are used to pivotally connect the equalizer link to the dozer'scab. In addition, bearings in each end of the equalizer link are used topivotally connect each end of the equalizer link to a roller frameassembly that includes the dozer's moving tracks or wheels. The endbearings accommodate relative movements between the equalizer link andthe roller frame assemblies. The end bearings typically are constructedof hardened steel that can be subject to substantial wear anddegradation during dozer operation. Although the end bearings are sealedand lubricated, the bearings can ultimately fail and require replacementafter about 1,000-3,000 hours of dozer operation. Such bearing failurecan result from unavoidable exposure to dirt, mud, and debris, whichadversely effect the bearings' lubrication.

When the end bearings fail, articulation of the associated joints isrestricted, and ultimately can lead to a failure of the end joints ofthe equalizer link. Typically, such bearing failure necessitates costlyrepair of the retaining ring grooves, seals, and/or bores of the endjoints of the equalizer link. For example, a major repair of theequalizer link end joints can cost several thousand dollars, andtypically removes a dozer from service for about one week. In order tominimize the possibility of bearing failure, conventional lubricated endbearings must be regularly inspected, lubricated, and otherwisemaintained.

Based on the foregoing, there is a need for a dozer equalizer link endbearing that requires less maintenance and is less prone to failure thanlubricated steel bearings. In particular, there is a need for anelastomeric end bearing assembly for use in connecting the ends of adozer equalizer link to its roller track frames.

SUMMARY OF THE INVENTION

The invention includes a tracked vehicle suspension system including atleast one elastomeric bearing assembly. The elastomeric bearing assemblycan include a substantially cylindrical outer member, a substantiallycylindrical elastomeric portion coupled to the cylindrical outer member,and a shim coupled to the substantially cylindrical elastomeric portion.The elastomeric bearing assembly can further include a substantiallyfrustospherical elastomeric section coupled to the shim, and an innermember coupled to the frustospherical elastomeric portion.

The invention also includes a tracked vehicle suspension system thatincludes at least one elastomeric bearing. The elastomeric bearing caninclude at least one substantially cylindrical elastomeric portion, atleast one substantially frustospherical elastomeric portion, and atleast one metal shim disposed between and bonded to the substantiallycylindrical elastomeric portion and the substantially frustosphericalelastomeric portion.

The invention further includes a tracked vehicle. The vehicle caninclude a first moving track roller frame assembly, and a second movingtrack roller frame assembly. The vehicle also can include an equalizerlink coupled to the first and second moving track roller frameassemblies. The link can include a first end portion and a second endportion, and a first elastomeric bearing at least partially coupling thefirst end portion to the first moving track roller frame assembly. Thebearing can include at least one substantially cylindrical elastomericportion, at least one substantially frustospherical elastomeric portion,and at least one metal shim disposed between and bonded to thesubstantially cylindrical elastomeric portion and the substantiallyfrustospherical elastomeric portion.

In an embodiment the invention includes a tracked vehicle suspensionsystem that includes at least one elastomeric bearing with at least afirst substantially cylindrical inner elastomeric portion, at least afirst substantially frustospherical outer elastomeric portion, and atleast a first nonelastomeric nonextensible shim disposed between andbonded to the substantially cylindrical inner elastomeric portion andthe first substantially frustospherical outer elastomeric portion.Preferably the at least one elastomeric bearing includes at least asecond substantially frustospherical outer elastomeric portion, and atleast a second outer nonelastomeric nonextensible shim disposed betweenand bonded to the first substantially frustospherical elastomericportion and the second substantially frustospherical elastomericportion.

These and other aspects of the invention will be understood from areading of the following description together with the drawings. It isto be understood that both the foregoing general description and thefollowing detailed description are exemplary of the invention, and areintended to provide an overview or framework for understanding thenature and character of the invention as it is claimed. The accompanyingdrawings are included to provide a further understanding of theinvention, and are incorporated in and constitute a part of thisspecification. The drawings illustrate various embodiments of theinvention, and together with the description serve to explain theprincipals and operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of a tracked earth-moving vehicle havinga suspension system according to the invention.

FIG. 2 is a cross-sectional view of the tracked earth-moving vehicle ofFIG. 1 taken along line 2-2 in FIG. 1.

FIG. 3 is a front elevation view of an equalizer link portion of thetracked earth-moving vehicle shown in FIGS. 1 and 2.

FIG. 4 is a perspective view showing a pinned connection between an endportion of the equalizer link of FIG. 3 connected to a moving trackframe of the tracked earth-moving vehicle shown in FIGS. 1 and 2.

FIG. 5 is a cross-sectional view of the pinned connection shown in FIG.4 taken along FIG. 5-5 in FIG. 1.

FIG. 6 is a perspective view of one embodiment of an elastomeric bearingportion of the pinned connection shown in FIGS. 4 and 5.

FIG. 7 is an end view of the elastomeric bearing shown in FIG. 6.

FIG. 8 is a longitudinal cross-sectional view of the bearing shown inFIGS. 6 and 7 taken along line 8-8 in FIG. 7.

FIG. 9 is a cross-sectional view of a mold for bond-molding elastomericlayers between the non-extensible, non-elastomeric portions of a bearinglike that shown in FIG. 8.

FIG. 10 is an enlarged detail view of the cross-section of FIG. 8.

FIG. 11 is a partial longitudinal cross-sectional view of an alternativeembodiment of an elastomeric bearing assembly for use in a pinnedconnection such as shown in FIGS. 4 and 5.

FIG. 12A-N show views of an embodiment of an elastomeric bearingassembly for use in a pinned connection such as shown in FIGS. 4 and 5with the elastomeric bearing assembly including two frustosphericalelastomeric portions concentrically disposed around the cylindricalelastomeric portion.

FIG. 13A-F illustrate an embodiment of an elastomeric bearing assemblyfor use in a pinned connection such as shown in FIGS. 4 and 5 with theelastomeric bearing assembly including two frustospherical elastomericportions concentrically disposed around the cylindrical elastomericportion, including exploded views with the elastomeric portions removedto show the nonelastomeric members.

DETAILED DESCRIPTION

Additional features and advantages of the invention will be set forth inthe detailed description which follows, and in part will be readilyapparent to those skilled in the art from that description or recognizedby practicing the invention as described herein, including the detaileddescription which follows, the claims, as well as the appended drawings.

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings.

One embodiment of the present invention is an elastomeric bearingassembly for use in conjunction with an equalizer link of a tractor orother earth-moving vehicle. The elastomeric bearing assembly includesboth a spherical and cylindrical rubber layer.

FIG. 1 and FIG. 2 show a dozer 100 equipped with elastomeric equalizerlink end bearings according to the invention. The dozer 100 includestracks 102 driven by sprockets 104 around wheels 34 mounted on trackroller frames 32. As shown in FIG. 2, the dozer 100 includes a pair ofopposed track roller frame assemblies 32, each connected to one end ofan equalizer link 10. The equalizer link 10 has opposed end portions, 18and 22, each having a substantially circular bore 52 extendingtherethrough. An elastomeric end bearing assembly 40 is disposed withineach of the bores 52. As shown in FIG. 1, each end bearing 40 receives apin 30 that also engages portions of an associated track roller frame32, thereby pivotally connecting each end 18, 22 of the equalizer link10 to one of the roller frames 32. As shown in FIG. 2, the equalizerlink 10 is connected at its center portion 14 to the dozer cab 110 by acenter pin 50 received in a center bearing 16.

FIG. 3 is a front view of the equalizer link 10. Equalizer link 10includes an elongated beam 12. The center portion 14 of the beam 12includes a cylindrical center bearing 16. FIG. 3 also shows elastomericend bearings 40 disposed within bores 52 in the end portions 18, 22 ofthe beam 12. The bearings 16, 40 provide means for pivotally connectingthe link 10 to the dozer cab 110, and pivotally connecting each rollertrack assembly 32 to the ends of the equalizer link 10. Such pivotalconnections permit articulated relative movement between the cab 110,the equalizer link 10, and the roller tracks 32 as a dozer traverses anuneven or irregular surface.

FIG. 4 is a perspective view of one end of an equalizer link 10connected to a roller track assembly 32. In FIG. 4, portions of theroller track assembly are broken away to reveal inner details of theconnection. As shown in FIG. 4, each end portion 18, 22 of the equalizerlink 10 is attached to a roller frame assembly 32 by an elongated pin 30that extends through an end bearing 40 and through opposed portions ofthe roller frame 32. In one embodiment, the end bearing 40 has aslightly larger outer diameter than the bore 52 in the equalizer link10, and is tightly and securely pressed into the bore 52. In addition,the pin 30 can have an outer diameter that is slightly larger than aninner bore diameter of the bearing 40, and can be tightly and securelypressed into the inner bore of the bearing 40.

FIG. 5 is a cross-sectional view of an equalizer link/track frameconnection like that shown in FIG. 4. As shown in FIG. 5, in oneembodiment, an elastomeric bearing assembly 40 can be disposed within asubstantially circular bore 52 extending through an end portion 18, 22of the beam 12 of equalizer link 10. A pin 30 extends through the bore52, and through opposed first and second substantially circular openings54, 56 that extend through opposed portions of the roller frame assembly32. The end portion 18, 22 of the equalizer link 10 is movably receivedwithin a space or gap 33 between the opposed portions of the trackroller frame 32. The pin 30 connects the end portion 18, 22 to the frame32, and permits at least some relative rotational displacement betweenthe end portion 18, 22 and frame 32 about substantially coincidentlongitudinal axes 60 of the pin 30 and bores 54, 56. As shown in FIG. 5,lateral clearances can be provided between the opposed frame portions 32and the end portions 18, 22 of the equalizer link 10 to permit at leastsome relative movement between the end portion 18, 22 and frame 32 in adirection that is parallel to the axis 60 of the pin 30.

FIGS. 6-9 show one embodiment of an elastomeric end bearing 40 for adozer equalizer link 10 according to the invention. As shown in FIG. 7,the bearing 40 includes an inner member 204 and an outer sleeve 200. Theinner member 204 includes a central bore 225 for receiving a pin 30 likethat shown in FIG. 5. As shown in FIG. 6, the outer sleeve 200 issubstantially cylindrical, and can include one or more axial slits 202along its length. In the embodiment shown in FIG. 7, the outer sleeve200 includes two diametrically opposed axial slits 202 thatsymmetrically divide the outer sleeve into first and second portions200A, 200B. The outer sleeve 200 has an outer diameter sized to betightly and securely received in a mating bore 52 in an equalizer link10, such as by mechanically pressing the outer sleeve 200 and endbearing 40 into the bore 52 with a hydraulic ram or the like. The outersleeve 200 can be constructed of metal such as steel, a metal alloy, acomposite material, or any other suitable substantially rigid andnon-extensible solid material. Preferably the non-extensiblenonelastomeric members of the bearing remain substantially unaltered insize and shape under applied load conditions, particularly when comparedto the temporary and recoverable deformations experienced by theelastomeric layers and elastomers under substantially identical loadconditions, most preferably with the nonextensible nonelastomericmembers formed from a metal.

As shown in FIGS. 7 and 8, the inner member is concentrically supportedwithin the outer sleeve 200 by a plurality of concentrically arrangedlayers or members 206, 221, and 222. As shown in FIG. 8, the innermember 204 can have a substantially frustospherical outer surface 205,and a substantially cylindrical inner surface 215 defining central bore225. The diameter of the cylindrical inner surface 215 can be sized toprovide tight and secure engagement with a mating pin 30 like that shownin FIG. 5. The inner member 204 can be constructed of a metal such assteel, a metal alloy, a composite material, or any other suitablesubstantially rigid and non-extensible solid material. As shown in FIG.8, the inner member 204 can have a length “L” that is shorter than thelength of the outer sleeve 200, and can be substantially centrallyaxially disposed within the outer sleeve 200.

As shown in FIG. 8, a shim 208 is concentrically disposed between theouter sleeve 200 and the inner member 204. In the embodiment shown inFIG. 8, the shim 208 has a substantially cylindrical outer surface 221and a substantially frustospherical inner surface 222. The shim 208 canbe constructed of a metal such as steel, a metal alloy, a compositematerial, or any other suitable substantially rigid and non-extensiblesolid material. As shown in FIG. 8, the shim 208 can be shorter inlength than the outer sleeve 200, and longer in length than length “L”of the inner member 204. The shim 208 can include counterbores 209A,209B on its ends that combine to define a central portion having anaxial length that is substantially equal to the length “L” of the innermember 204.

As shown in FIG. 8, the bearing 40 can include a first elastomeric layer210 concentrically disposed between the frustospherical outer surface205 of the inner member 204 and the frustospherical inner surface of theshim 208. In the embodiment shown, the first elastomeric layer 210 has asubstantially frustospherical shape. The first elastomeric layer 210 canbe constructed of rubber or another suitable elastomeric material. Inone embodiment, the first elastomeric layer 210 is composed of a naturalrubber elastomer. Also shown in FIG. 8, the bearing 40 can include asecond elastomeric layer 206 concentrically disposed between thesubstantially cylindrical outer surface 221 of the shim 208 and thesubstantially cylindrical inner surface of the outer sleeve 200. Thesecond elastomeric layer 206 can be constructed of rubber or anothersuitable elastomeric material. In one embodiment, the second elastomericlayer 206 is a natural rubber elastomer. Preferably, the firstelastomeric layer 210 and the second elastomeric layer 206 areconstructed of the same natural rubber material.

Adjacent portions of the first elastomeric layer 210 can be respectivelytightly bonded to the inner surface 222 of the shim 208, and to theouter surface 205 of the inner member 204. Similarly, adjacent portionsof the second elastomeric layer 206 can be respectively tightly bondedto the outer surface of the shim 208 and to the inner surface of theouter sleeve 200. The elastomeric layers 210, 206 can be molded betweenthe inner member 204, shim 208, and outer sleeve 200 after coating theaffected surfaces of the inner member 204, shim 208, and outer sleeve200 with a suitable adhesive.

Adjacent portions of the first elastomeric layer 210 can be respectivelysecurely bonded to the inner surface 222 of the shim 208, and to theouter surface 205 of the inner member 204. Similarly, adjacent portionsof the second elastomeric layer 206 can be respectively securely bondedto the outer surface of the shim 208 and to the inner surface of theouter sleeve 200. As shown in FIG. 9, the elastomeric layers 210, 206can be molded between the inner member 204, the shim 208, and the outersleeve 200. As shown in FIG. 9, the elastomeric layers 210, 206 can bemold-bonded to the adjacent contacting surfaces of the non-elastomericand non-extensible inner member 204, shim 208, and outer sleeve 200using a suitable mold 500. As shown in FIG. 9, the mold 500 can includea lower portion 502 and an upper portion 504 that combine to hold andposition the non-elastomeric bearing members 200, 204, 208 in concentricrelationship. Before placing the outer sleeve 200, the inner member 204and the shim 208 in the mold 500 and before injecting the uncuredelastomeric material 290 therebetween, the surfaces of the members 204,208, and 200 that will contact the elastomeric material 290 arethoroughly cleaned. In addition, a suitable elastomer-to-substrateadhesive (such as a suitable rubber-to-metal adhesive, for example) isapplied to the clean contacting surfaces of the members 204, 208, and200 before molding. A quantity of uncured elastomeric material 290 ispressed and transferred into the mold 500 through a plurality of spruesor inlets 510, thereby causing the uncured elastomeric material 290 toflow into and fill the interstices or voids between the inner member 204and shim 208, and between the shim 208 and outer sleeve 200. Theelastomeric material 290 is then cured to yield a mold-bondedelastomeric bearing assembly 40 with elastomeric layers 206, 210 likethat shown in FIG. 8.

As shown in FIG. 8, the second elastomeric layer 206 has a substantiallycylindrical configuration that bears and accommodates torsional loadsthat are applied to the inner member 204 of the bearing 40 by a pin 30borne within the bearing 40. Accordingly, the second elastomeric layer206 is a torsional-load carrying elastomeric layer. Conversely, thefirst elastomeric layer 210 has a substantially spherical configurationthat bears and tolerates cocking loads that are applied to the innermember 204 of the bearing 40 by a pin 30 borne within the bearing 40.Accordingly, the second elastomeric layer 206 is a cocking-load carryingelastomeric layer. Preferably, the bearing 40 includes at least onesubstantially frustospherical or spherical elastomeric layer 210 and atleast one substantially cylindrical elastomeric layer 206 such that thebearing includes both at least one torsional-load carrying elastomericlayer and at least one cocking-load carrying elastomeric layer.Accordingly, the bearing 40 is operable to withstand a combination ofcocking loads and torsional loads without failure. As a result, thebearing 40 is particularly well suited for use as an end bearing for anequalizer link 10 for a dozer 100 that typically is subjected to acombination of severe cocking loads and severe torsional loads.

FIG. 10 shows an enlarged view of a portion of the cross-sectional viewof the elastomeric bearing 40 shown in FIG. 8. As shown in FIG. 10, thefirst elastomeric layer 210 includes a recessed, smoothly contouredannular end portion 232. The opposite end of the first elastomeric layer210 can be substantially similarly shaped. When the first elastomericlayer 210 is compressed between the inner member 204 and shim 208 undercertain load conditions, portions of the first elastomeric layer 210respond by outwardly bulging in the region of the end portion 232. InFIG. 10, displacement of the surface of end portion 232 during bulgingof the first elastomeric layer 210 is depicted by dashed line 235. Theannular end portion 232 shown in FIG. 10 is configured such that theresulting shape factor minimizes peak stresses at the ends the firstelastomeric layer 210 during such bulging conditions such that peakstresses do not exceed the limits of the elastomeric material.Generally, a wider annular end portion 232 will experience lower peakstresses than a narrower end portion 232 under identical bulge-producingload conditions.

As also shown in FIG. 10, the second elastomeric layer 206 similarlyincludes a recessed, smoothly contoured annular end portion 230. Theopposite end of the second elastomeric layer 206 can be substantiallysimilarly shaped. When the second elastomeric layer 206 is compressedbetween the outer sleeve 200 and shim 208 under certain load conditions,portions of the second elastomeric layer 206 respond by outwardlybulging in the region of the end portion 230. In FIG. 10, displacementof the surface of end portion 230 during bulging of the secondelastomeric layer 206 is depicted by dashed line 237. The end portion230 shown in FIG. 10 is configured to provide a shape factor thatminimizes that peak stresses at the ends the second elastomeric layer206 during such bulge-inducing load. As discussed above, generallyspeaking, a wider annular end portion 230 will experience lower peakstresses than a narrower annular end portion 230 under the identicalbulge-producing load conditions. Referring to FIG. 10, in order tomaximize the width “w” of the end portion 230 and minimize bulge-inducedstresses in the end portion 230, the shim 208 can include areduced-diameter end portion or “step” 220, thereby providing a widerannular gap and more desirable shape factor in the area of end portion230.

As shown in FIG. 7, the first elastomeric layer 204, shim 208, andsecond elastomeric layer 206 can include diametrically opposed slits 202that coincide with the slits 202 in the outer sleeve 200. When thebearing 40 is installed in an equalizer link 10, the bearing 40typically is press fit into a mating circular bore 52. As the bearing 40is pressed into the bore 52, the two halves 200A, 200B of the outersleeve 200 are radially inwardly displaced such that the secondelastomeric layer 206 is radially pre-compressed between the outersleeve 200 and the shim 208. As the second elastomeric layer ispre-compressed, the two halves 208A, 208B of the shim 208 also areradially inwardly displaced such that the first elastomeric layer 210 isradially pre-compressed between the shim 208 and the inner member 204.In one embodiment, the uncompressed outer diameter of the bearing 40 isabout 105% of the inner diameter of a receiving circular bore 52.Pre-compression of the elastomeric layers 206, 210 increases theeffective load bearing capacity of the elastomeric layers.

FIG. 11 shows an alternative embodiment of a dozer equalizer linkelastomeric bearing 140 according to the invention. In this embodiment,an outer sleeve 1200 has a substantially cylindrical outer surface and afrustospherical inner surface 1221. A substantially cylindrical innermember 1204 is concentrically disposed within the outer sleeve 1200. Ashim 1208 has a substantially cylindrical inner surface and asubstantially frustospherical outer surface 1222, and is concentricallydisposed between the outer sleeve 1200 and the inner member 1204. Asubstantially cylindrical first elastomeric layer is disposed betweenthe inner member and the shim 1208. A substantially frustosphericalsecond elastomeric layer 1206 is disposed between the outer sleeve 1200and the shim 1208. As can be seen by comparing FIG. 11 to FIG. 8, thebearing 140 is similar to bearing 40, but its frustosphericalelastomeric layer is an outer elastomeric layer, and its cylindricalelastomeric layer is an innermost elastomeric layer. In this alternativeembodiment, the frustospherical elastomeric layer 1206 of bearing 140durably reacts to applied cocking loads. In addition, in thisalternative embodiment, the cylindrical elastomeric layer 1210 ofbearing 140 durably reacts to torsional loads. Bearing 140 otherwise issubstantially similar to bearing 40 described above.

A bearing 40, 140 according to the invention is capable of accommodatingcocking displacement up to about 6 degrees or more. In other words, anelastomeric bearing 40, 140 according to the invention permits a pin 30received in a central bore 225, 1225 of the bearing 40, 140 to rotate upto about 6 degrees or more about an axis that is transverse to thelongitudinal axis of the pin 30 and bearing 40, 140. In addition, anelastomeric bearing 40, 140 according to the invention permits a pin 30fixedly received in a central bore 225, 1225 of the bearing 40, 140 torotate up to about 15 degrees or more about its longitudinal axis.

Preferably the elastomeric portions are elastomeric bodies, preferablymolded elastomeric shell bodies, and most preferably molded elastomericshell bodies having inner bonding surfaces and outer bonding surfaces.Preferably the molded elastomeric shell bodies are split elastomericshell bodies split into upper and lower split elastomeric shell bodyhalves.

Various embodiments of the present invention are described above.However, it will be appreciated that modifications and variations of thepresent invention also are within the scope of the invention. Forexample, though a dozer equalizer link bearing has been principallydescribed as having two concentric elastomeric layers, a bearingaccording to the invention can include more than two elastomeric layers.In addition, a bearing according to the invention can include more thanone substantially cylindrical elastomeric layer, and/or can include morethan one substantially spherical or frustospherical elastomeric layer.Still further, though the elastomeric bearings principally have beendescribed as being used to pivotally connect an end portion of anequalizer link to a roller track frame, such bearings also can be usedto pivotally connect an equalizer link to a cab portion of a dozer orother tracked vehicle.

In an embodiment the invention includes a vehicle suspension systemcomprising an elastomeric bearing assembly. Preferably the elastomericbearing assembly includes a substantially cylindrical elastomericportion and a substantially frustospherical elastomeric portion.Preferably the elastomeric bearing assembly includes a nonelastomericshim with a substantially cylindrical surface and a substantiallyfrustospherical surface. FIGS. 12 and 13 show preferred elastomericbearing assemblies. Preferably the elastomeric bearing assembly includesa substantially cylindrical elastomeric portion 3000 and a substantiallyfrustospherical elastomeric portion 3001. Preferably the elastomericbearing assembly includes a nonelastomeric shim 3002 with asubstantially cylindrical surface 3003 and a substantiallyfrustospherical surface 3004.

In an embodiment the invention includes a tracked vehicle suspensionsystem comprising at least one elastomeric bearing. Preferably theelastomeric bearing includes at least one substantially cylindricalelastomeric portion 3000, at least one substantially frustosphericalelastomeric portion 3001, and at least one substantially nonextensibleshim 3002 disposed between and bonded to the substantially cylindricalelastomeric portion 3000 and the substantially frustosphericalelastomeric portion 3001. In a preferred embodiment the substantiallyfrustospherical elastomeric portion is substantially concentricallydisposed within the substantially cylindrical elastomeric portion. In apreferred embodiment the substantially cylindrical elastomeric portionis substantially concentrically disposed within the substantiallyfrustospherical elastomeric portion. Preferably the elastomeric bearingfurther comprises at least a second substantially frustospherical outerelastomeric portion 3010 and at least a second substantiallynonextensible shim 3011 disposed between and bonded to the secondsubstantially frustospherical outer elastomeric portion 3010 and thefirst substantially frustospherical elastomeric portion 3001.

Preferably the elastomeric bearing comprises at least a secondsubstantially frustospherical elastomeric portion 3010 and at least asecond substantially nonextensible nonelastomeric shim 3011 having asubstantially frustospherical shim elastomer inner bonding surface 3012and a substantially frustospherical shim elastomer outer bonding surface3013. Preferably the substantially cylindrical elastomeric portion, thesubstantially frustospherical elastomeric portion; and the shim eachinclude at least one longitudinal split 3020 extending through at leasta portion thereof.

In an embodiment the invention includes a tracked vehicle. Preferablythe tracked vehicle includes a first moving track roller frame assembly;a second moving track roller frame assembly; an equalizer link coupledto the first and second moving track roller frame assembly, the linkcomprising a first end portion and a second end portion. Preferably thetracked vehicle includes a first elastomeric bearing at least partiallycoupling the first end portion to the first moving track roller frameassembly. Preferably the first elastomeric bearing assembly includes atleast one substantially cylindrical elastomeric portion, at least onefirst substantially frustospherical elastomeric portion, and at leastone substantially nonextensible shim disposed between and bonded to thesubstantially cylindrical elastomeric portion and the substantiallyfrustospherical elastomeric portion. In an embodiment the substantiallyfrustospherical elastomeric portion is substantially concentricallydisposed within the substantially cylindrical elastomeric portion. In anembodiment preferably the substantially cylindrical elastomeric portionis substantially concentrically disposed within the first substantiallyfrustospherical elastomeric portion. Preferably the elastomeric bearingincludes at least a second substantially frustospherical outerelastomeric portion 3010 and at least a second substantiallyfrustospherical outer nonextensible bonded shim 3011, the secondsubstantially frustospherical outer nonextensible bonded shim and thesecond substantially frustospherical outer elastomeric portionsubstantially concentrically disposed around the outside of the firstsubstantially frustospherical elastomeric portion 3001 with thesubstantially cylindrical elastomeric portion 3000 substantiallyconcentrically disposed within. Preferably the elastomeric bearingsubstantially cylindrical elastomeric portion 3000 is an elongatedoutwardly extending substantially cylindrical elastomeric portion, withthe elongated outwardly extending substantially cylindrical elastomericportion extending axially along a bore axis 3030 out below the firstsubstantially frustospherical elastomeric portion 3001 and the secondsubstantially frustospherical outer elastomeric portion 3010.

Preferably the substantially cylindrical elastomeric portion, thesubstantially frustospherical elastomeric portion, and the shims allinclude a first and second opposing longitudinal splits extendingthrough portions thereof, with the substantially cylindrical elastomericportion comprised of an upper split half cylindrical elastomeric portionand a lower split half cylindrical elastomeric portion, with thesubstantially frustospherical elastomeric portion comprised of an uppersplit half frustospherical elastomeric portion and a lower split halffrustospherical elastomeric portion, and with the shim comprised of anupper split shim half and a lower split shim half with a load directiondirected downward through the lower split shim half. Preferably thesubstantially cylindrical elastomeric portion 3000, the substantiallyfrustospherical elastomeric portion 3001, and the shims 3002 all includea first and second opposing longitudinal splits 3020 extending throughportions thereof, with the substantially cylindrical elastomeric portioncomprised of an upper split half cylindrical elastomeric portion 3100and a lower split half cylindrical elastomeric portion 3101, with thesubstantially frustospherical elastomeric portion comprised of an uppersplit half frustospherical elastomeric portion 3102 and a lower splithalf frustospherical elastomeric portion 3103, and with the shimcomprised of an upper split shim half 3104 and a lower split shim half3105 with a load direction directed downward through the lower splitshim half 3105. Preferably the elastomeric bearing assembly of thetracked vehicle couples the link end and the moving track roller frameassembly with a downward load direction applied from a received pin 30downward through a nonsplit nonelastomeric inner member 3106, through alower split half cylindrical elastomeric portion 3101, through a lowersplit shim half 3105, and through a lower split half frustosphericalelastomeric portion 3103. Preferably the downward load direction isfurther applied down through a second outer lower split frustosphericalnonelastomeric shim half 3110, through a second outer lower split halffrustospherical elastomeric portion 3111, and through a lower splitnonelastomeric outer member half 3112.

Preferably the tracked vehicle includes a second elastomeric bearing atleast partially coupling the second end portion to the second movingtrack roller frame assembly, the second elastomeric bearing the secondelastomeric bearing comprising at least one substantially cylindricalinner elastomeric portion 3000; at least one first substantiallyfrustospherical elastomeric portion 3001; at least one substantiallynonextensible shim 3002 disposed between and bonded to the substantiallycylindrical elastomeric portion and the substantially frustosphericalelastomeric portion; and at least a second substantially frustosphericalouter elastomeric portion 3010 and at least a second substantiallyfrustospherical outer nonextensible bonded shim 3011, the secondsubstantially frustospherical outer nonextensible bonded shim 3011 andthe second substantially frustospherical outer elastomeric portion 3010substantially concentrically disposed around the outside of the firstsubstantially frustospherical elastomeric portion 3001 with thesubstantially cylindrical elastomeric portion 3000 substantiallyconcentrically disposed within the first substantially frustosphericalelastomeric portion 3001, wherein the substantially cylindricalelastomeric portion 3000 is an elongated outwardly extendingsubstantially cylindrical elastomeric portion, with the elongatedoutwardly extending substantially cylindrical elastomeric portionextending axially along a bore axis 3030 out below the firstsubstantially frustospherical elastomeric portion and the secondsubstantially frustospherical outer elastomeric portion.

Preferably the tracked vehicle substantially cylindrical elastomericportion comprises a torsional load carrying elastomer, and thesubstantially frustospherical elastomeric portion comprises a cockingload carrying elastomer with the elastomeric bearing providing a cockingdisplacement of at least 2 degrees and a rotation of at least 6 degrees.Preferably the tracked vehicle elastomeric bearing has a vehicleoperation durability life of at least 1000 hours with the bearingcarrying a plurality of torsional and cocking loads during the vehicleoperation durability life. Preferably the elastomeric bearing includesat least a second substantially frustospherical outer elastomericportion 3010 and at least a second substantially frustospherical outernonextensible bonded shim 3011, the second substantially frustosphericalouter nonextensible bonded shim 3011 and the second substantiallyfrustospherical outer elastomeric portion 3010 substantiallyconcentrically disposed around the outside of the first substantiallyfrustospherical elastomeric portion 3001 with the substantiallycylindrical elastomeric portion 3000 substantially concentricallydisposed within the first substantially frustospherical elastomericportion 3001. Preferably the second substantially frustospherical outerelastomeric portion 3010 has a balanced second substantiallyfrustospherical outer elastomeric portion outside diameter, insidediameter, thickness, and length providing a second substantiallyfrustospherical outer elastomeric portion elastomer fatigue life.Preferably the first substantially frustospherical elastomeric portion3001 has a balanced first substantially frustospherical outerelastomeric portion outside diameter, inside diameter, thickness, andlength providing a first substantially frustospherical outer elastomericportion elastomer fatigue life. Preferably the substantially cylindricalelastomeric portion 3000 has a balanced substantially cylindricalelastomeric portion outside diameter, inside diameter, thickness, andlength, providing a substantially cylindrical elastomeric portionelastomer fatigue life wherein the second substantially frustosphericalouter elastomeric portion elastomer fatigue life is proximate the firstsubstantially frustospherical outer elastomeric portion elastomerfatigue life which is proximate the substantially cylindricalelastomeric portion elastomer fatigue life. Preferably the firstsubstantially frustospherical elastomeric portion has a balanced firstsubstantially frustospherical elastomeric portion outside diameter,inside diameter, thickness, and length providing a first substantiallyfrustospherical outer elastomeric portion elastomer fatigue life and thesubstantially cylindrical elastomeric portion has a balancedsubstantially cylindrical elastomeric portion outside diameter, insidediameter, thickness, and length, providing a substantially cylindricalelastomeric portion elastomer fatigue life wherein the firstsubstantially frustospherical outer elastomeric portion elastomerfatigue life is proximate the substantially cylindrical elastomericportion elastomer fatigue life. In an embodiment the first substantiallyfrustospherical elastomeric portion is substantially concentricallydisposed within the substantially cylindrical elastomeric portion. In anembodiment the substantially cylindrical elastomeric portion issubstantially concentrically disposed within the first substantiallyfrustospherical elastomeric portion.

In an embodiment the invention includes an elastomeric bearing assemblyfor a vehicle suspension system. Preferably the elastomeric bearingassembly includes at least one substantially cylindrical elastomericportion; at least a first substantially frustospherical elastomericportion; and at least a first substantially nonextensible elastomericshim disposed between and bonded to the substantially cylindricalelastomeric portion and the substantially frustospherical elastomericportion. Preferably the substantially cylindrical elastomeric portion,the first substantially frustospherical elastomeric portion, and thefirst substantially nonextensible elastomeric shim are concentricallycentered around a center bore axis 3030. Preferably the firstsubstantially nonextensible nonelastomeric shim has a first end portionand a distal second end portion. Preferably the substantiallyfrustospherical elastomeric portion has a spherical shape terminating ata first end portion and a distal second end portion. Preferably thesubstantially cylindrical elastomeric portion has a first end portionand a distal second end portion, the substantially cylindricalelastomeric first end portion elongated outwardly extending axiallyalong the bore axis out beyond the substantially frustosphericalelastomeric first end portion, and the substantially cylindricalelastomeric second end portion elongated outwardly extending axiallyalong the bore axis out beyond the substantially frustosphericalelastomeric second end portion. In an embodiment the substantiallyfrustospherical elastomeric first end portion and distal second endportion are substantially thicker than at least one other thinnerportion of the substantially frustospherical elastomeric portion. In anembodiment the substantially cylindrical elastomeric first end portionand distal second end portion are substantially thicker than at leastone other thinner portion of the substantially cylindrical elastomericportion. In an embodiment the elastomeric bearing assembly includes asecond outer substantially frustospherical elastomeric portion having asecond outer spherical shape terminating at a second outer substantiallyfrustospherical elastomeric first end portion and a second outersubstantially frustospherical elastomeric distal second end portion,wherein the substantially cylindrical elastomeric first end portionelongated outwardly extending axially along the bore axis 3030 outbeyond second outer substantially frustospherical elastomeric first endportion and the substantially cylindrical elastomeric second end portionelongated outwardly extending axially along the bore axis 3030 outbeyond second outer substantially frustospherical elastomeric distalsecond end portion. In an embodiment the elastomeric bearing assemblyincludes at least one nonextensible nonelastomeric member with a firstdiameter proximate to a thinner portion and a second diameter proximateto a thicker end portion, and wherein the first diameter is larger thanthe second diameter.

In an embodiment the invention includes a method of making a vehiclesuspension system elastomeric bearing assembly. The method of making avehicle suspension system elastomeric bearing assembly includesproviding a substantially cylindrical shaped elastomeric layer disposedbetween a first nonextensible nonelastomeric member surface and a secondnonextensible nonelastomeric member surface, with the first and secondnonextensible nonelastomeric member surfaces configured such that thesubstantially cylindrical elastomeric layer therebetween includes an endportion that is substantially thicker than at least one other thinnerportion of the substantially cylindrical elastomeric layer. The methodincludes providing a substantially frustospherical shaped elastomericlayer disposed between a third nonextensible nonelastomeric membersurface and a fourth nonextensible nonelastomeric member surface, thefourth and third nonextensible nonelastomeric members are configuredsuch that the substantially frustospherical elastomeric layertherebetween includes an end portion that is substantially thicker thanat least one other thinner portion of the substantially frustosphericalelastomeric layer.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the invention withoutdeparting from the spirit and scope of the invention. Thus, it isintended that the invention cover the modifications and variations ofthis invention provided they come within the scope of the appendedclaims and their equivalents. It is intended that the scope of differingterms or phrases in the claims may be fulfilled by the same or differentstructure(s) or step(s).

1. A vehicle suspension system comprising an elastomeric bearingassembly, the elastomeric bearing assembly comprising: a substantiallycylindrical outer member; a substantially cylindrical elastomericportion coupled to said cylindrical outer member; a shim coupled to saidsubstantially cylindrical elastomeric portion; a substantiallyfrustospherical elastomeric section coupled to said shim; and an innermember coupled to said frustospherical elastomeric portion.
 2. Thevehicle suspension system of claim 1, wherein said shim comprises asubstantially cylindrical outer surface and a substantiallyfrustospherical inner surface.
 3. The vehicle suspension system of claim2, wherein said shim comprises a middle portion, a first end, and asecond end, and wherein the first and second ends have diameters thatare smaller than a diameter of the middle portion.
 4. A tracked vehiclesuspension system comprising: at least one elastomeric bearingcomprising: at least one substantially cylindrical elastomeric portion;at least one substantially frustospherical elastomeric portion; and atleast one substantially non-extensible shim disposed between and bondedto the substantially cylindrical elastomeric portion and thesubstantially frustospherical elastomeric portion.
 5. A tracked vehiclesuspension system according to claim 4 wherein the substantiallyfrustospherical elastomeric portion is substantially concentricallydisposed within the substantially cylindrical elastomeric portion.
 6. Atracked vehicle suspension system according to claim 4 wherein thesubstantially cylindrical elastomeric portion is substantiallyconcentrically disposed within the substantially frustosphericalelastomeric portion.
 7. A tracked vehicle suspension system according toclaim 6 wherein the elastomeric bearing further comprises at least asecond substantially frustospherical outer elastomeric portion and atleast a second substantially nonextensible shim disposed between andbonded to the second substantially frustospherical outer elastomericportion and the one substantially frustospherical elastomeric portion.8. A tracked vehicle suspension system according to claim 4 wherein theelastomeric bearing further comprises at least a second substantiallyfrustospherical elastomeric portion and at least a second substantiallynonextensible nonelastomeric shim having a substantially frustosphericalshim elastomer inner bonding surface and a substantially frustosphericalshim elastomer outer bonding surface.
 9. A tracked vehicle suspensionsystem according to claim 4 wherein the substantially cylindricalelastomeric portion, the substantially frustospherical elastomericportion; and the shim each include at least one longitudinal splitextending through at least a portion thereof.
 10. A tracked vehiclecomprising: a first moving track roller frame assembly; a second movingtrack roller frame assembly; an equalizer link coupled to said first andsecond moving track roller frame assembly, said link comprising a firstend portion and a second end portion; a first elastomeric bearing atleast partially coupling said first end portion to said first movingtrack roller frame assembly, said first elastomeric bearing assemblycomprising: at least one substantially cylindrical elastomeric portion;at least one first substantially frustospherical elastomeric portion;and at least one substantially non-extensible shim disposed between andbonded to the substantially cylindrical elastomeric portion and thesubstantially frustospherical elastomeric portion.
 11. A tracked vehicleaccording to claim 10 wherein the substantially frustosphericalelastomeric portion is substantially concentrically disposed within thesubstantially cylindrical elastomeric portion.
 12. A tracked vehicleaccording to claim 10 wherein the substantially cylindrical elastomericportion is substantially concentrically disposed within the firstsubstantially frustospherical elastomeric portion.
 13. A tracked vehicleaccording to claim 12 wherein the elastomeric bearing includes at leasta second substantially frustospherical outer elastomeric portion and atleast a second substantially frustospherical outer nonextensible bondedshim, said second substantially frustospherical outer nonextensiblebonded shim and said second substantially frustospherical outerelastomeric portion substantially concentrically disposed around theoutside of the first substantially frustospherical elastomeric portionwith the substantially cylindrical elastomeric portion substantiallyconcentrically disposed within.
 14. A tracked vehicle according to claim13 wherein the elastomeric bearing substantially cylindrical elastomericportion is an elongated outwardly extending substantially cylindricalelastomeric portion, with the elongated outwardly extendingsubstantially cylindrical elastomeric portion extending axially along abore axis out below said first substantially frustospherical elastomericportion and said second substantially frustospherical outer elastomericportion.
 15. A tracked vehicle according to claim 10 wherein thesubstantially cylindrical elastomeric portion, the substantiallyfrustospherical elastomeric portion, and the shim each include at leastone longitudinal split extending through at least a portion thereof,with the substantially cylindrical elastomeric portion comprised of anupper split half cylindrical elastomeric portion and a lower split halfcylindrical elastomeric portion, with the substantially frustosphericalelastomeric portion comprised of an upper split half frustosphericalelastomeric portion and a lower split half frustospherical elastomericportion, and with the shim comprised of an upper split shim half and alower split shim half with a load direction directed downward throughsaid lower split shim half.
 16. A tracked vehicle according to claim 10and further comprising a second elastomeric bearing at least partiallycoupling the second end portion to said second moving track roller frameassembly, said second elastomeric bearing said second elastomericbearing comprising: at least one substantially cylindrical innerelastomeric portion; at least one first substantially frustosphericalelastomeric portion; at least one substantially nonextensible shimdisposed between and bonded to the substantially cylindrical elastomericportion and the substantially frustospherical elastomeric portion; atleast a second substantially frustospherical outer elastomeric portionand at least a second substantially frustospherical outer nonextensiblebonded shim, said second substantially frustospherical outernonextensible bonded shim and said second substantially frustosphericalouter elastomeric portion substantially concentrically disposed aroundthe outside of the first substantially frustospherical elastomericportion with the substantially cylindrical elastomeric portionsubstantially concentrically disposed within said first substantiallyfrustospherical elastomeric portion, wherein the substantiallycylindrical elastomeric portion is an elongated outwardly extendingsubstantially cylindrical elastomeric portion, with the elongatedoutwardly extending substantially cylindrical elastomeric portionextending axially along a bore axis out below said first substantiallyfrustospherical elastomeric portion and said second substantiallyfrustospherical outer elastomeric portion.
 17. A tracked vehicleaccording to claim 10, wherein the substantially cylindrical elastomericportion comprises a torsional load carrying elastomer, and thesubstantially frustospherical elastomeric portion comprises a cockingload carrying elastomer, and wherein the first elastomeric bearingprovides a cocking displacement of at least 2 degrees and a rotation ofat least 6 degrees.
 18. A tracked vehicle according to claim 10, whereinsaid first elastomeric bearing has a vehicle operation durability lifeof at least 1000 hours with said bearing carrying a plurality oftorsional and cocking loads during said vehicle operation durabilitylife.
 19. A tracked vehicle according to claim 18 wherein said firstelastomeric bearing includes at least a second substantiallyfrustospherical outer elastomeric portion and at least a secondsubstantially frustospherical outer nonextensible bonded shim, saidsecond substantially frustospherical outer nonextensible bonded shim andsaid second substantially frustospherical outer elastomeric portionsubstantially concentrically disposed around the outside of the firstsubstantially frustospherical elastomeric portion with the substantiallycylindrical elastomeric portion substantially concentrically disposedwithin said first substantially frustospherical elastomeric portion. 20.A tracked vehicle according to claim 19, said second substantiallyfrustospherical outer elastomeric portion having a balanced secondsubstantially frustospherical outer elastomeric portion outsidediameter, inside diameter, thickness, and length providing a secondsubstantially frustospherical outer elastomeric portion elastomerfatigue life; said first substantially frustospherical outer elastomericportion having a balanced first substantially frustospherical outerelastomeric portion outside diameter, inside diameter, thickness, andlength providing a first substantially frustospherical outer elastomericportion elastomer fatigue life; said substantially cylindricalelastomeric portion having a balanced substantially cylindricalelastomeric portion outside diameter, inside diameter, thickness, andlength, providing a substantially cylindrical elastomeric portionelastomer fatigue life wherein said second substantially frustosphericalouter elastomeric portion elastomer fatigue life proximates said firstsubstantially frustospherical outer elastomeric portion elastomerfatigue life which proximates said substantially cylindrical elastomericportion elastomer fatigue life.
 21. An elastomeric bearing assembly fora vehicle suspension system, the elastomeric bearing assemblycomprising: at least one substantially cylindrical elastomeric portion;at least a first substantially frustospherical elastomeric portion; atleast a first substantially nonextensible nonelastomeric shim disposedbetween and bonded to the substantially cylindrical elastomeric portionand the substantially frustospherical elastomeric portion; saidsubstantially cylindrical elastomeric portion, said first substantiallyfrustospherical elastomeric portion, and said first substantiallynonextensible nonelastomeric shim concentrically centered around acenter bore axis, said first substantially nonextensible nonelastomericshim having a first end portion and a distal second end portion, saidsubstantially frustospherical elastomeric portion having a sphericalshape terminating at a first end portion and a distal second endportion, said substantially cylindrical elastomeric portion having afirst end portion and a distal second end portion, said substantiallycylindrical elastomeric first end portion elongated outwardly extendingaxially along said bore axis out beyond said substantiallyfrustospherical elastomeric first end portion, and said substantiallycylindrical elastomeric second end portion elongated outwardly extendingaxially along said bore axis out beyond said substantiallyfrustospherical elastomeric second end portion.
 22. An elastomericbearing assembly according to claim 21 said substantiallyfrustospherical elastomeric first end portion and distal second endportion are substantially thicker than at least one other thinnerportion of said substantially frustospherical elastomeric portion, saidsubstantially cylindrical elastomeric first end portion and distalsecond end portion are substantially thicker than at least one otherthinner portion of said substantially cylindrical elastomeric portion.23. An elastomeric bearing assembly according to claim 21, including asecond outer substantially frustospherical elastomeric portion having asecond outer spherical shape terminating at a second outer substantiallyfrustospherical elastomeric first end portion and a second outersubstantially frustospherical elastomeric distal second end portion,wherein said substantially cylindrical elastomeric first end portionelongated outwardly extending axially along said bore axis out beyondsecond outer substantially frustospherical elastomeric first end portionand said substantially cylindrical elastomeric second end portionelongated outwardly extending axially along said bore axis out beyondsecond outer substantially frustospherical elastomeric distal second endportion.
 24. An elastomeric bearing assembly according to claim 21including at least one non-extensible nonelastomeric member with a firstdiameter proximate to a thinner portion and a second diameter proximateto a thicker end portion, and wherein the first diameter is larger thanthe second diameter.
 25. A method of making a vehicle suspension systemelastomeric bearing assembly, the method of making a vehicle suspensionsystem elastomeric bearing assembly comprising: providing asubstantially cylindrical shaped elastomeric layer disposed between afirst nonextensible nonelastomeric member surface and a secondnonextensible nonelastomeric member surface, with the first and secondnonextensible nonelastomeric member surfaces configured such that thesubstantially cylindrical elastomeric layer therebetween includes an endportion that is substantially thicker than at least one other thinnerportion of the substantially cylindrical elastomeric layer, andproviding a substantially frustospherical shaped elastomeric layerdisposed between a third nonextensible nonelastomeric member surface anda fourth nonextensible nonelastomeric member surface, the fourth andthird nonextensible nonelastomeric members are configured such that thesubstantially frustospherical elastomeric layer therebetween includes anend portion that is substantially thicker than at least one otherthinner portion of the substantially frustospherical elastomeric layer.